Police spokesman Imran Shaukat said the attack took place as the vehicle reached near the headquarters of paramilitary forces called the Rangers in Karachi, Pakistan’s largest city, the capital of southern Sindh province.

Pakistani Taliban spokesman Ahsanullah Ahsan claimed responsibility, saying they targeted the Rangers for working against them.

Dr. Seemi Jamali said the bodies of the three dead officers arrived at her government hospital. She said three security personnel and one civilian were wounded in the attack.

Karachi has a long history of such incidents. It has also been the scene of political and sectarian violence in recent years.

The latest attack underscored concerns that militants could step up the pace of attacks ahead of the parliamentary elections, scheduled for May.